Loop-induced Neutrino Non-Standard Interactions

TL;DR

This paper proposes a novel loop-induced mechanism for generating neutrino non-standard interactions (NSI), which can produce sizable effects without conflicting with collider or flavor violation constraints.

Contribution

It introduces a new loop process approach to generate neutrino NSI, expanding beyond traditional Fierz transformation methods in scalar extensions of the Standard Model.

Findings

Loop-induced NSI can reach sizes of 0.1 to 1 relative to Fermi interaction.

The approach can generate neutrino-quark NSI.

This method circumvents strong collider and flavor violation constraints.

Abstract

Non-Standard Interactions (NSI) of neutrinos may originate from models in which new particles interact with neutrinos. In scalar extensions of the SM, the typical approach to obtain NSI requires Fierz transformations and charged Higgses, which suffer from strong constraints from collider searches or charged lepton flavor violation processes. We propose here an alternative approach to generate NSI, namely via loop processes. We show that such loop-induced NSI from secret neutrino interactions can reach sizes of ${\cal O}(0.1\sim1)$ compared to standard Fermi interaction. This approach can also give rise to neutrino-quark NSI.